Many wireless devices are capable of wireless communication with other devices using both wireless local area network (WLAN) signals and Bluetooth (BT) signals. For example, many laptops, netbook computers, and tablet devices use WLAN signals (also commonly referred to as Wi-Fi signals) to wirelessly connect to networks such as the Internet and/or private networks, and use Bluetooth signals to communicate with local BT-enabled devices such as headsets, printers, scanners, and the like. Wi-Fi communications are governed by the IEEE 802.11 family of standards, and Bluetooth communications are governed by the IEEE 802.15 family of standards.
To concurrently transmit both Wi-Fi signals and Bluetooth signals (e.g., to transmit information to the network via Wi-Fi signals while transmitting audio information to a BT-enabled headset), wireless devices typically use a first external antenna and a first associated power amplifier for the transmission of the Wi-Fi signals, and use a second external antenna and a second associated power amplifier for the transmission of the Bluetooth signals. Separate power amplifiers and antennas are typically used for the transmission of Wi-Fi signals and Bluetooth signals because of difficulties associated with concurrently transmitting Wi-Fi signals and Bluetooth signals using the same power amplifier. More specifically, conventional attempts to concurrently process Wi-Fi and Bluetooth signals in the same power amplifier typically cause the power amplifier to operate in a non-linear manner that can lead to the generation of undesirable out-of-band spectral components (e.g., intermodulation products) that violate FCC out-of-band emission limits.
Thus, although faster wireless connections to the network can be achieved by employing a second Wi-Fi channel, another antenna and associated power amplifier are typically required to accommodate the additional Wi-Fi channel. Unfortunately, because many wireless devices such as laptops include only two external antennas and associated power amplifiers, the use of two Wi-Fi channels in such wireless devices typically precludes the concurrent use of Bluetooth signals, which is undesirable. Thus, there is a need to enable the concurrent transmission of multiple Wi-Fi channels and one or more Bluetooth signals using only two pairs of antennas and power amplifiers in a manner that does not cause unacceptable signal distortion and that does not violate FCC out-of-band emission limits.
Like reference numerals refer to corresponding parts throughout the drawing figures.